From d06bfd1989fe97623b32d6df4ffa6e4338c99dc8 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Wed, 7 Jun 2017 23:06:55 -0400 Subject: random: warn when kernel uses unseeded randomness This enables an important dmesg notification about when drivers have used the crng without it being seeded first. Prior, these errors would occur silently, and so there hasn't been a great way of diagnosing these types of bugs for obscure setups. By adding this as a config option, we can leave it on by default, so that we learn where these issues happen, in the field, will still allowing some people to turn it off, if they really know what they're doing and do not want the log entries. However, we don't leave it _completely_ by default. An earlier version of this patch simply had `default y`. I'd really love that, but it turns out, this problem with unseeded randomness being used is really quite present and is going to take a long time to fix. Thus, as a compromise between log-messages-for-all and nobody-knows, this is `default y`, except it is also `depends on DEBUG_KERNEL`. This will ensure that the curious see the messages while others don't have to. Signed-off-by: Jason A. Donenfeld Signed-off-by: Theodore Ts'o --- lib/Kconfig.debug | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'lib/Kconfig.debug') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index e4587ebe52c7..c4159605bfbf 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1209,6 +1209,22 @@ config STACKTRACE It is also used by various kernel debugging features that require stack trace generation. +config WARN_UNSEEDED_RANDOM + bool "Warn when kernel uses unseeded randomness" + default y + depends on DEBUG_KERNEL + help + Some parts of the kernel contain bugs relating to their use of + cryptographically secure random numbers before it's actually possible + to generate those numbers securely. This setting ensures that these + flaws don't go unnoticed, by enabling a message, should this ever + occur. This will allow people with obscure setups to know when things + are going wrong, so that they might contact developers about fixing + it. + + Say Y here, unless you simply do not care about using unseeded + randomness and do not want a potential warning message in your logs. + config DEBUG_KOBJECT bool "kobject debugging" depends on DEBUG_KERNEL -- cgit v1.3-14-g43fede From 0f789b67647205b77dee56fcc27a7d8de3fcd52e Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Mon, 10 Jul 2017 15:51:43 -0700 Subject: lib/interval_tree_test.c: allow the module to be compiled-in Patch series "lib/interval_tree_test: some debugging improvements". Here are some patches that update the interval_tree_test module allowing users to pass finer grained options to run the actual test. This patch (of 4): It is a tristate after all, and also serves well for quick debugging. Link: http://lkml.kernel.org/r/20170518174936.20265-2-dave@stgolabs.net Signed-off-by: Davidlohr Bueso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/Kconfig.debug') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index ca9460f049b8..e20fc079bebd 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1594,7 +1594,7 @@ config RBTREE_TEST config INTERVAL_TREE_TEST tristate "Interval tree test" - depends on m && DEBUG_KERNEL + depends on DEBUG_KERNEL select INTERVAL_TREE help A benchmark measuring the performance of the interval tree library -- cgit v1.3-14-g43fede From 9308f2f9e7f055cf3934645ec622bb5259dc1c14 Mon Sep 17 00:00:00 2001 From: "Luis R. Rodriguez" Date: Wed, 12 Jul 2017 14:33:43 -0700 Subject: test_sysctl: add dedicated proc sysctl test driver The existing tools/testing/selftests/sysctl/ tests include two test cases, but these use existing production kernel sysctl interfaces. We want to expand test coverage but we can't just be looking for random safe production values to poke at, that's just insane! Instead just dedicate a test driver for debugging purposes and port the existing scripts to use it. This will make it easier for further tests to be added. Subsequent patches will extend our test coverage for sysctl. The stress test driver uses a new license (GPL on Linux, copyleft-next outside of Linux). Linus was fine with this [0] and later due to Ted's and Alans's request ironed out an "or" language clause to use [1] which is already present upstream. [0] https://lkml.kernel.org/r/CA+55aFyhxcvD+q7tp+-yrSFDKfR0mOHgyEAe=f_94aKLsOu0Og@mail.gmail.com [1] https://lkml.kernel.org/r/1495234558.7848.122.camel@linux.intel.com Link: http://lkml.kernel.org/r/20170630224431.17374-2-mcgrof@kernel.org Signed-off-by: Luis R. Rodriguez Acked-by: Kees Cook Cc: "Eric W. Biederman" Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 11 +++ lib/Makefile | 1 + lib/test_sysctl.c | 113 ++++++++++++++++++++++++ tools/testing/selftests/sysctl/config | 1 + tools/testing/selftests/sysctl/run_numerictests | 4 +- tools/testing/selftests/sysctl/run_stringtests | 4 +- 6 files changed, 130 insertions(+), 4 deletions(-) create mode 100644 lib/test_sysctl.c create mode 100644 tools/testing/selftests/sysctl/config (limited to 'lib/Kconfig.debug') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index e20fc079bebd..f28f4252e54a 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1785,6 +1785,17 @@ config TEST_FIRMWARE If unsure, say N. +config TEST_SYSCTL + tristate "sysctl test driver" + default n + depends on PROC_SYSCTL + help + This builds the "test_sysctl" module. This driver enables to test the + proc sysctl interfaces available to drivers safely without affecting + production knobs which might alter system functionality. + + If unsure, say N. + config TEST_UDELAY tristate "udelay test driver" default n diff --git a/lib/Makefile b/lib/Makefile index 5a008329324e..85e91e51a9fe 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -46,6 +46,7 @@ obj-$(CONFIG_TEST_HEXDUMP) += test_hexdump.o obj-y += kstrtox.o obj-$(CONFIG_TEST_BPF) += test_bpf.o obj-$(CONFIG_TEST_FIRMWARE) += test_firmware.o +obj-$(CONFIG_TEST_SYSCTL) += test_sysctl.o obj-$(CONFIG_TEST_HASH) += test_hash.o test_siphash.o obj-$(CONFIG_TEST_KASAN) += test_kasan.o obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o diff --git a/lib/test_sysctl.c b/lib/test_sysctl.c new file mode 100644 index 000000000000..b2163bfb6eb2 --- /dev/null +++ b/lib/test_sysctl.c @@ -0,0 +1,113 @@ +/* + * proc sysctl test driver + * + * Copyright (C) 2017 Luis R. Rodriguez + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or at your option any + * later version; or, when distributed separately from the Linux kernel or + * when incorporated into other software packages, subject to the following + * license: + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of copyleft-next (version 0.3.1 or later) as published + * at http://copyleft-next.org/. + */ + +/* + * This module provides an interface to the the proc sysctl interfaces. This + * driver requires CONFIG_PROC_SYSCTL. It will not normally be loaded by the + * system unless explicitly requested by name. You can also build this driver + * into your kernel. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static int i_zero; +static int i_one_hundred = 100; + +struct test_sysctl_data { + int int_0001; + char string_0001[65]; +}; + +static struct test_sysctl_data test_data = { + .int_0001 = 60, + .string_0001 = "(none)", +}; + +/* These are all under /proc/sys/debug/test_sysctl/ */ +static struct ctl_table test_table[] = { + { + .procname = "int_0001", + .data = &test_data.int_0001, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &i_zero, + .extra2 = &i_one_hundred, + }, + { + .procname = "string_0001", + .data = &test_data.string_0001, + .maxlen = sizeof(test_data.string_0001), + .mode = 0644, + .proc_handler = proc_dostring, + }, + { } +}; + +static struct ctl_table test_sysctl_table[] = { + { + .procname = "test_sysctl", + .maxlen = 0, + .mode = 0555, + .child = test_table, + }, + { } +}; + +static struct ctl_table test_sysctl_root_table[] = { + { + .procname = "debug", + .maxlen = 0, + .mode = 0555, + .child = test_sysctl_table, + }, + { } +}; + +static struct ctl_table_header *test_sysctl_header; + +static int __init test_sysctl_init(void) +{ + test_sysctl_header = register_sysctl_table(test_sysctl_root_table); + if (!test_sysctl_header) + return -ENOMEM; + return 0; +} +late_initcall(test_sysctl_init); + +static void __exit test_sysctl_exit(void) +{ + if (test_sysctl_header) + unregister_sysctl_table(test_sysctl_header); +} + +module_exit(test_sysctl_exit); + +MODULE_AUTHOR("Luis R. Rodriguez "); +MODULE_LICENSE("GPL"); diff --git a/tools/testing/selftests/sysctl/config b/tools/testing/selftests/sysctl/config new file mode 100644 index 000000000000..6ca14800d755 --- /dev/null +++ b/tools/testing/selftests/sysctl/config @@ -0,0 +1 @@ +CONFIG_TEST_SYSCTL=y diff --git a/tools/testing/selftests/sysctl/run_numerictests b/tools/testing/selftests/sysctl/run_numerictests index e6e76c93d948..c375ce0f4c15 100755 --- a/tools/testing/selftests/sysctl/run_numerictests +++ b/tools/testing/selftests/sysctl/run_numerictests @@ -1,7 +1,7 @@ #!/bin/sh -SYSCTL="/proc/sys" -TARGET="${SYSCTL}/vm/swappiness" +SYSCTL="/proc/sys/debug/test_sysctl/" +TARGET="${SYSCTL}/int_0001" ORIG=$(cat "${TARGET}") TEST_STR=$(( $ORIG + 1 )) diff --git a/tools/testing/selftests/sysctl/run_stringtests b/tools/testing/selftests/sysctl/run_stringtests index 857ec667fb02..a6f2618afeaa 100755 --- a/tools/testing/selftests/sysctl/run_stringtests +++ b/tools/testing/selftests/sysctl/run_stringtests @@ -1,7 +1,7 @@ #!/bin/sh -SYSCTL="/proc/sys" -TARGET="${SYSCTL}/kernel/domainname" +SYSCTL="/proc/sys/debug/test_sysctl/" +TARGET="${SYSCTL}/string_0001" ORIG=$(cat "${TARGET}") TEST_STR="Testing sysctl" -- cgit v1.3-14-g43fede From 05a4a95279311c3a4633b4277a5d21cfd616c6c7 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Wed, 12 Jul 2017 14:35:46 -0700 Subject: kernel/watchdog: split up config options Split SOFTLOCKUP_DETECTOR from LOCKUP_DETECTOR, and split HARDLOCKUP_DETECTOR_PERF from HARDLOCKUP_DETECTOR. LOCKUP_DETECTOR implies the general boot, sysctl, and programming interfaces for the lockup detectors. An architecture that wants to use a hard lockup detector must define HAVE_HARDLOCKUP_DETECTOR_PERF or HAVE_HARDLOCKUP_DETECTOR_ARCH. Alternatively an arch can define HAVE_NMI_WATCHDOG, which provides the minimum arch_touch_nmi_watchdog, and it otherwise does its own thing and does not implement the LOCKUP_DETECTOR interfaces. sparc is unusual in that it has started to implement some of the interfaces, but not fully yet. It should probably be converted to a full HAVE_HARDLOCKUP_DETECTOR_ARCH. [npiggin@gmail.com: fix] Link: http://lkml.kernel.org/r/20170617223522.66c0ad88@roar.ozlabs.ibm.com Link: http://lkml.kernel.org/r/20170616065715.18390-4-npiggin@gmail.com Signed-off-by: Nicholas Piggin Reviewed-by: Don Zickus Reviewed-by: Babu Moger Tested-by: Babu Moger [sparc] Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/Kconfig | 25 ++++- arch/powerpc/Kconfig | 1 + arch/powerpc/kernel/setup_64.c | 2 +- arch/x86/Kconfig | 1 + arch/x86/kernel/apic/hw_nmi.c | 2 +- include/linux/nmi.h | 29 +++-- kernel/Makefile | 2 +- kernel/sysctl.c | 31 +++--- kernel/watchdog.c | 243 +++++++++++++++++++++++++++-------------- kernel/watchdog_hld.c | 32 ------ lib/Kconfig.debug | 45 +++++--- 11 files changed, 251 insertions(+), 162 deletions(-) (limited to 'lib/Kconfig.debug') diff --git a/arch/Kconfig b/arch/Kconfig index cae0958a2298..fb9bd7d36b05 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -198,9 +198,6 @@ config HAVE_KPROBES_ON_FTRACE config HAVE_NMI bool -config HAVE_NMI_WATCHDOG - depends on HAVE_NMI - bool # # An arch should select this if it provides all these things: # @@ -288,6 +285,28 @@ config HAVE_PERF_EVENTS_NMI subsystem. Also has support for calculating CPU cycle events to determine how many clock cycles in a given period. +config HAVE_HARDLOCKUP_DETECTOR_PERF + bool + depends on HAVE_PERF_EVENTS_NMI + help + The arch chooses to use the generic perf-NMI-based hardlockup + detector. Must define HAVE_PERF_EVENTS_NMI. + +config HAVE_NMI_WATCHDOG + depends on HAVE_NMI + bool + help + The arch provides a low level NMI watchdog. It provides + asm/nmi.h, and defines its own arch_touch_nmi_watchdog(). + +config HAVE_HARDLOCKUP_DETECTOR_ARCH + bool + select HAVE_NMI_WATCHDOG + help + The arch chooses to provide its own hardlockup detector, which is + a superset of the HAVE_NMI_WATCHDOG. It also conforms to config + interfaces and parameters provided by hardlockup detector subsystem. + config HAVE_PERF_REGS bool help diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 7177a3f4f418..63ed758e1d20 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -197,6 +197,7 @@ config PPC select HAVE_OPTPROBES if PPC64 select HAVE_PERF_EVENTS select HAVE_PERF_EVENTS_NMI if PPC64 + select HAVE_HARDLOCKUP_DETECTOR_PERF if HAVE_PERF_EVENTS_NMI select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP select HAVE_RCU_TABLE_FREE if SMP diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index 4640f6d64f8b..074a075a9cdb 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -752,7 +752,7 @@ struct ppc_pci_io ppc_pci_io; EXPORT_SYMBOL(ppc_pci_io); #endif -#ifdef CONFIG_HARDLOCKUP_DETECTOR +#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF u64 hw_nmi_get_sample_period(int watchdog_thresh) { return ppc_proc_freq * watchdog_thresh; diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 94a18681353d..3d2b8ce54e00 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -162,6 +162,7 @@ config X86 select HAVE_PCSPKR_PLATFORM select HAVE_PERF_EVENTS select HAVE_PERF_EVENTS_NMI + select HAVE_HARDLOCKUP_DETECTOR_PERF if HAVE_PERF_EVENTS_NMI select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP select HAVE_REGS_AND_STACK_ACCESS_API diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c index c73c9fb281e1..d6f387780849 100644 --- a/arch/x86/kernel/apic/hw_nmi.c +++ b/arch/x86/kernel/apic/hw_nmi.c @@ -19,7 +19,7 @@ #include #include -#ifdef CONFIG_HARDLOCKUP_DETECTOR +#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF u64 hw_nmi_get_sample_period(int watchdog_thresh) { return (u64)(cpu_khz) * 1000 * watchdog_thresh; diff --git a/include/linux/nmi.h b/include/linux/nmi.h index bd387ef8bccd..8aa01fd859fb 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -11,13 +11,21 @@ #endif #ifdef CONFIG_LOCKUP_DETECTOR +void lockup_detector_init(void); +#else +static inline void lockup_detector_init(void) +{ +} +#endif + +#ifdef CONFIG_SOFTLOCKUP_DETECTOR extern void touch_softlockup_watchdog_sched(void); extern void touch_softlockup_watchdog(void); extern void touch_softlockup_watchdog_sync(void); extern void touch_all_softlockup_watchdogs(void); extern unsigned int softlockup_panic; -extern unsigned int hardlockup_panic; -void lockup_detector_init(void); +extern int soft_watchdog_enabled; +extern atomic_t watchdog_park_in_progress; #else static inline void touch_softlockup_watchdog_sched(void) { @@ -31,9 +39,6 @@ static inline void touch_softlockup_watchdog_sync(void) static inline void touch_all_softlockup_watchdogs(void) { } -static inline void lockup_detector_init(void) -{ -} #endif #ifdef CONFIG_DETECT_HUNG_TASK @@ -63,15 +68,18 @@ static inline void reset_hung_task_detector(void) #if defined(CONFIG_HARDLOCKUP_DETECTOR) extern void hardlockup_detector_disable(void); +extern unsigned int hardlockup_panic; #else static inline void hardlockup_detector_disable(void) {} #endif -#if defined(CONFIG_HARDLOCKUP_DETECTOR) || defined(CONFIG_HAVE_NMI_WATCHDOG) +#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) extern void arch_touch_nmi_watchdog(void); #else +#if !defined(CONFIG_HAVE_NMI_WATCHDOG) static inline void arch_touch_nmi_watchdog(void) {} #endif +#endif /** * touch_nmi_watchdog - restart NMI watchdog timeout. @@ -141,15 +149,18 @@ static inline bool trigger_single_cpu_backtrace(int cpu) } #endif -#ifdef CONFIG_LOCKUP_DETECTOR +#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF u64 hw_nmi_get_sample_period(int watchdog_thresh); +#endif + +#ifdef CONFIG_LOCKUP_DETECTOR extern int nmi_watchdog_enabled; -extern int soft_watchdog_enabled; extern int watchdog_user_enabled; extern int watchdog_thresh; extern unsigned long watchdog_enabled; +extern struct cpumask watchdog_cpumask; extern unsigned long *watchdog_cpumask_bits; -extern atomic_t watchdog_park_in_progress; +extern int __read_mostly watchdog_suspended; #ifdef CONFIG_SMP extern int sysctl_softlockup_all_cpu_backtrace; extern int sysctl_hardlockup_all_cpu_backtrace; diff --git a/kernel/Makefile b/kernel/Makefile index 72aa080f91f0..4cb8e8b23c6e 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -82,7 +82,7 @@ obj-$(CONFIG_KPROBES) += kprobes.o obj-$(CONFIG_KGDB) += debug/ obj-$(CONFIG_DETECT_HUNG_TASK) += hung_task.o obj-$(CONFIG_LOCKUP_DETECTOR) += watchdog.o -obj-$(CONFIG_HARDLOCKUP_DETECTOR) += watchdog_hld.o +obj-$(CONFIG_HARDLOCKUP_DETECTOR_PERF) += watchdog_hld.o obj-$(CONFIG_SECCOMP) += seccomp.o obj-$(CONFIG_RELAY) += relay.o obj-$(CONFIG_SYSCTL) += utsname_sysctl.o diff --git a/kernel/sysctl.c b/kernel/sysctl.c index df9f2a367882..6648fbbb8157 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -900,6 +900,14 @@ static struct ctl_table kern_table[] = { .extra2 = &zero, #endif }, + { + .procname = "watchdog_cpumask", + .data = &watchdog_cpumask_bits, + .maxlen = NR_CPUS, + .mode = 0644, + .proc_handler = proc_watchdog_cpumask, + }, +#ifdef CONFIG_SOFTLOCKUP_DETECTOR { .procname = "soft_watchdog", .data = &soft_watchdog_enabled, @@ -909,13 +917,6 @@ static struct ctl_table kern_table[] = { .extra1 = &zero, .extra2 = &one, }, - { - .procname = "watchdog_cpumask", - .data = &watchdog_cpumask_bits, - .maxlen = NR_CPUS, - .mode = 0644, - .proc_handler = proc_watchdog_cpumask, - }, { .procname = "softlockup_panic", .data = &softlockup_panic, @@ -925,27 +926,29 @@ static struct ctl_table kern_table[] = { .extra1 = &zero, .extra2 = &one, }, -#ifdef CONFIG_HARDLOCKUP_DETECTOR +#ifdef CONFIG_SMP { - .procname = "hardlockup_panic", - .data = &hardlockup_panic, + .procname = "softlockup_all_cpu_backtrace", + .data = &sysctl_softlockup_all_cpu_backtrace, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, .extra2 = &one, }, +#endif /* CONFIG_SMP */ #endif -#ifdef CONFIG_SMP +#ifdef CONFIG_HARDLOCKUP_DETECTOR { - .procname = "softlockup_all_cpu_backtrace", - .data = &sysctl_softlockup_all_cpu_backtrace, + .procname = "hardlockup_panic", + .data = &hardlockup_panic, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, .extra2 = &one, }, +#ifdef CONFIG_SMP { .procname = "hardlockup_all_cpu_backtrace", .data = &sysctl_hardlockup_all_cpu_backtrace, @@ -957,6 +960,8 @@ static struct ctl_table kern_table[] = { }, #endif /* CONFIG_SMP */ #endif +#endif + #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86) { .procname = "unknown_nmi_panic", diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 03e0b69bb5bf..1fba9c3d66dc 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -29,15 +29,58 @@ #include #include +/* Watchdog configuration */ static DEFINE_MUTEX(watchdog_proc_mutex); -#if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR) -unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED|NMI_WATCHDOG_ENABLED; +int __read_mostly nmi_watchdog_enabled; + +#if defined(CONFIG_HARDLOCKUP_DETECTOR) || defined(CONFIG_HAVE_NMI_WATCHDOG) +unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED | + NMI_WATCHDOG_ENABLED; #else unsigned long __read_mostly watchdog_enabled = SOFT_WATCHDOG_ENABLED; #endif -int __read_mostly nmi_watchdog_enabled; + +#ifdef CONFIG_HARDLOCKUP_DETECTOR +/* boot commands */ +/* + * Should we panic when a soft-lockup or hard-lockup occurs: + */ +unsigned int __read_mostly hardlockup_panic = + CONFIG_BOOTPARAM_HARDLOCKUP_PANIC_VALUE; +/* + * We may not want to enable hard lockup detection by default in all cases, + * for example when running the kernel as a guest on a hypervisor. In these + * cases this function can be called to disable hard lockup detection. This + * function should only be executed once by the boot processor before the + * kernel command line parameters are parsed, because otherwise it is not + * possible to override this in hardlockup_panic_setup(). + */ +void hardlockup_detector_disable(void) +{ + watchdog_enabled &= ~NMI_WATCHDOG_ENABLED; +} + +static int __init hardlockup_panic_setup(char *str) +{ + if (!strncmp(str, "panic", 5)) + hardlockup_panic = 1; + else if (!strncmp(str, "nopanic", 7)) + hardlockup_panic = 0; + else if (!strncmp(str, "0", 1)) + watchdog_enabled &= ~NMI_WATCHDOG_ENABLED; + else if (!strncmp(str, "1", 1)) + watchdog_enabled |= NMI_WATCHDOG_ENABLED; + return 1; +} +__setup("nmi_watchdog=", hardlockup_panic_setup); + +#endif + +#ifdef CONFIG_SOFTLOCKUP_DETECTOR int __read_mostly soft_watchdog_enabled; +#endif + int __read_mostly watchdog_user_enabled; int __read_mostly watchdog_thresh = 10; @@ -45,15 +88,9 @@ int __read_mostly watchdog_thresh = 10; int __read_mostly sysctl_softlockup_all_cpu_backtrace; int __read_mostly sysctl_hardlockup_all_cpu_backtrace; #endif -static struct cpumask watchdog_cpumask __read_mostly; +struct cpumask watchdog_cpumask __read_mostly; unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask); -/* Helper for online, unparked cpus. */ -#define for_each_watchdog_cpu(cpu) \ - for_each_cpu_and((cpu), cpu_online_mask, &watchdog_cpumask) - -atomic_t watchdog_park_in_progress = ATOMIC_INIT(0); - /* * The 'watchdog_running' variable is set to 1 when the watchdog threads * are registered/started and is set to 0 when the watchdog threads are @@ -72,7 +109,27 @@ static int __read_mostly watchdog_running; * of 'watchdog_running' cannot change while the watchdog is deactivated * temporarily (see related code in 'proc' handlers). */ -static int __read_mostly watchdog_suspended; +int __read_mostly watchdog_suspended; + +/* + * These functions can be overridden if an architecture implements its + * own hardlockup detector. + */ +int __weak watchdog_nmi_enable(unsigned int cpu) +{ + return 0; +} +void __weak watchdog_nmi_disable(unsigned int cpu) +{ +} + +#ifdef CONFIG_SOFTLOCKUP_DETECTOR + +/* Helper for online, unparked cpus. */ +#define for_each_watchdog_cpu(cpu) \ + for_each_cpu_and((cpu), cpu_online_mask, &watchdog_cpumask) + +atomic_t watchdog_park_in_progress = ATOMIC_INIT(0); static u64 __read_mostly sample_period; @@ -120,6 +177,7 @@ static int __init softlockup_all_cpu_backtrace_setup(char *str) return 1; } __setup("softlockup_all_cpu_backtrace=", softlockup_all_cpu_backtrace_setup); +#ifdef CONFIG_HARDLOCKUP_DETECTOR static int __init hardlockup_all_cpu_backtrace_setup(char *str) { sysctl_hardlockup_all_cpu_backtrace = @@ -128,6 +186,7 @@ static int __init hardlockup_all_cpu_backtrace_setup(char *str) } __setup("hardlockup_all_cpu_backtrace=", hardlockup_all_cpu_backtrace_setup); #endif +#endif /* * Hard-lockup warnings should be triggered after just a few seconds. Soft- @@ -213,18 +272,6 @@ void touch_softlockup_watchdog_sync(void) __this_cpu_write(watchdog_touch_ts, 0); } -/* watchdog detector functions */ -bool is_hardlockup(void) -{ - unsigned long hrint = __this_cpu_read(hrtimer_interrupts); - - if (__this_cpu_read(hrtimer_interrupts_saved) == hrint) - return true; - - __this_cpu_write(hrtimer_interrupts_saved, hrint); - return false; -} - static int is_softlockup(unsigned long touch_ts) { unsigned long now = get_timestamp(); @@ -237,21 +284,21 @@ static int is_softlockup(unsigned long touch_ts) return 0; } -static void watchdog_interrupt_count(void) +/* watchdog detector functions */ +bool is_hardlockup(void) { - __this_cpu_inc(hrtimer_interrupts); -} + unsigned long hrint = __this_cpu_read(hrtimer_interrupts); -/* - * These two functions are mostly architecture specific - * defining them as weak here. - */ -int __weak watchdog_nmi_enable(unsigned int cpu) -{ - return 0; + if (__this_cpu_read(hrtimer_interrupts_saved) == hrint) + return true; + + __this_cpu_write(hrtimer_interrupts_saved, hrint); + return false; } -void __weak watchdog_nmi_disable(unsigned int cpu) + +static void watchdog_interrupt_count(void) { + __this_cpu_inc(hrtimer_interrupts); } static int watchdog_enable_all_cpus(void); @@ -502,57 +549,6 @@ static void watchdog_unpark_threads(void) kthread_unpark(per_cpu(softlockup_watchdog, cpu)); } -/* - * Suspend the hard and soft lockup detector by parking the watchdog threads. - */ -int lockup_detector_suspend(void) -{ - int ret = 0; - - get_online_cpus(); - mutex_lock(&watchdog_proc_mutex); - /* - * Multiple suspend requests can be active in parallel (counted by - * the 'watchdog_suspended' variable). If the watchdog threads are - * running, the first caller takes care that they will be parked. - * The state of 'watchdog_running' cannot change while a suspend - * request is active (see related code in 'proc' handlers). - */ - if (watchdog_running && !watchdog_suspended) - ret = watchdog_park_threads(); - - if (ret == 0) - watchdog_suspended++; - else { - watchdog_disable_all_cpus(); - pr_err("Failed to suspend lockup detectors, disabled\n"); - watchdog_enabled = 0; - } - - mutex_unlock(&watchdog_proc_mutex); - - return ret; -} - -/* - * Resume the hard and soft lockup detector by unparking the watchdog threads. - */ -void lockup_detector_resume(void) -{ - mutex_lock(&watchdog_proc_mutex); - - watchdog_suspended--; - /* - * The watchdog threads are unparked if they were previously running - * and if there is no more active suspend request. - */ - if (watchdog_running && !watchdog_suspended) - watchdog_unpark_threads(); - - mutex_unlock(&watchdog_proc_mutex); - put_online_cpus(); -} - static int update_watchdog_all_cpus(void) { int ret; @@ -604,6 +600,81 @@ static void watchdog_disable_all_cpus(void) } } +#else /* SOFTLOCKUP */ +static int watchdog_park_threads(void) +{ + return 0; +} + +static void watchdog_unpark_threads(void) +{ +} + +static int watchdog_enable_all_cpus(void) +{ + return 0; +} + +static void watchdog_disable_all_cpus(void) +{ +} + +static void set_sample_period(void) +{ +} +#endif /* SOFTLOCKUP */ + +/* + * Suspend the hard and soft lockup detector by parking the watchdog threads. + */ +int lockup_detector_suspend(void) +{ + int ret = 0; + + get_online_cpus(); + mutex_lock(&watchdog_proc_mutex); + /* + * Multiple suspend requests can be active in parallel (counted by + * the 'watchdog_suspended' variable). If the watchdog threads are + * running, the first caller takes care that they will be parked. + * The state of 'watchdog_running' cannot change while a suspend + * request is active (see related code in 'proc' handlers). + */ + if (watchdog_running && !watchdog_suspended) + ret = watchdog_park_threads(); + + if (ret == 0) + watchdog_suspended++; + else { + watchdog_disable_all_cpus(); + pr_err("Failed to suspend lockup detectors, disabled\n"); + watchdog_enabled = 0; + } + + mutex_unlock(&watchdog_proc_mutex); + + return ret; +} + +/* + * Resume the hard and soft lockup detector by unparking the watchdog threads. + */ +void lockup_detector_resume(void) +{ + mutex_lock(&watchdog_proc_mutex); + + watchdog_suspended--; + /* + * The watchdog threads are unparked if they were previously running + * and if there is no more active suspend request. + */ + if (watchdog_running && !watchdog_suspended) + watchdog_unpark_threads(); + + mutex_unlock(&watchdog_proc_mutex); + put_online_cpus(); +} + #ifdef CONFIG_SYSCTL /* @@ -810,9 +881,11 @@ int proc_watchdog_cpumask(struct ctl_table *table, int write, * a temporary cpumask, so we are likely not in a * position to do much else to make things better. */ +#ifdef CONFIG_SOFTLOCKUP_DETECTOR if (smpboot_update_cpumask_percpu_thread( &watchdog_threads, &watchdog_cpumask) != 0) pr_err("cpumask update failed\n"); +#endif } } out: diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c index 90d688df6ce1..295a0d84934c 100644 --- a/kernel/watchdog_hld.c +++ b/kernel/watchdog_hld.c @@ -22,39 +22,7 @@ static DEFINE_PER_CPU(bool, hard_watchdog_warn); static DEFINE_PER_CPU(bool, watchdog_nmi_touch); static DEFINE_PER_CPU(struct perf_event *, watchdog_ev); -/* boot commands */ -/* - * Should we panic when a soft-lockup or hard-lockup occurs: - */ -unsigned int __read_mostly hardlockup_panic = - CONFIG_BOOTPARAM_HARDLOCKUP_PANIC_VALUE; static unsigned long hardlockup_allcpu_dumped; -/* - * We may not want to enable hard lockup detection by default in all cases, - * for example when running the kernel as a guest on a hypervisor. In these - * cases this function can be called to disable hard lockup detection. This - * function should only be executed once by the boot processor before the - * kernel command line parameters are parsed, because otherwise it is not - * possible to override this in hardlockup_panic_setup(). - */ -void hardlockup_detector_disable(void) -{ - watchdog_enabled &= ~NMI_WATCHDOG_ENABLED; -} - -static int __init hardlockup_panic_setup(char *str) -{ - if (!strncmp(str, "panic", 5)) - hardlockup_panic = 1; - else if (!strncmp(str, "nopanic", 7)) - hardlockup_panic = 0; - else if (!strncmp(str, "0", 1)) - watchdog_enabled &= ~NMI_WATCHDOG_ENABLED; - else if (!strncmp(str, "1", 1)) - watchdog_enabled |= NMI_WATCHDOG_ENABLED; - return 1; -} -__setup("nmi_watchdog=", hardlockup_panic_setup); void arch_touch_nmi_watchdog(void) { diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index f28f4252e54a..b0d01c6d4e03 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -778,34 +778,45 @@ config DEBUG_SHIRQ menu "Debug Lockups and Hangs" config LOCKUP_DETECTOR - bool "Detect Hard and Soft Lockups" + bool + +config SOFTLOCKUP_DETECTOR + bool "Detect Soft Lockups" depends on DEBUG_KERNEL && !S390 + select LOCKUP_DETECTOR help Say Y here to enable the kernel to act as a watchdog to detect - hard and soft lockups. + soft lockups. Softlockups are bugs that cause the kernel to loop in kernel mode for more than 20 seconds, without giving other tasks a chance to run. The current stack trace is displayed upon detection and the system will stay locked up. +config HARDLOCKUP_DETECTOR_PERF + bool + select SOFTLOCKUP_DETECTOR + +# +# arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard +# lockup detector rather than the perf based detector. +# +config HARDLOCKUP_DETECTOR + bool "Detect Hard Lockups" + depends on DEBUG_KERNEL && !S390 + depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH + select LOCKUP_DETECTOR + select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF + select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH + help + Say Y here to enable the kernel to act as a watchdog to detect + hard lockups. + Hardlockups are bugs that cause the CPU to loop in kernel mode for more than 10 seconds, without letting other interrupts have a chance to run. The current stack trace is displayed upon detection and the system will stay locked up. - The overhead should be minimal. A periodic hrtimer runs to - generate interrupts and kick the watchdog task every 4 seconds. - An NMI is generated every 10 seconds or so to check for hardlockups. - - The frequency of hrtimer and NMI events and the soft and hard lockup - thresholds can be controlled through the sysctl watchdog_thresh. - -config HARDLOCKUP_DETECTOR - def_bool y - depends on LOCKUP_DETECTOR && !HAVE_NMI_WATCHDOG - depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI - config BOOTPARAM_HARDLOCKUP_PANIC bool "Panic (Reboot) On Hard Lockups" depends on HARDLOCKUP_DETECTOR @@ -826,7 +837,7 @@ config BOOTPARAM_HARDLOCKUP_PANIC_VALUE config BOOTPARAM_SOFTLOCKUP_PANIC bool "Panic (Reboot) On Soft Lockups" - depends on LOCKUP_DETECTOR + depends on SOFTLOCKUP_DETECTOR help Say Y here to enable the kernel to panic on "soft lockups", which are bugs that cause the kernel to loop in kernel @@ -843,7 +854,7 @@ config BOOTPARAM_SOFTLOCKUP_PANIC config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE int - depends on LOCKUP_DETECTOR + depends on SOFTLOCKUP_DETECTOR range 0 1 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC default 1 if BOOTPARAM_SOFTLOCKUP_PANIC @@ -851,7 +862,7 @@ config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE config DETECT_HUNG_TASK bool "Detect Hung Tasks" depends on DEBUG_KERNEL - default LOCKUP_DETECTOR + default SOFTLOCKUP_DETECTOR help Say Y here to enable the kernel to detect "hung tasks", which are bugs that cause the task to be stuck in -- cgit v1.3-14-g43fede From d9c6a72d6fa29d3a7999dda726577e5d1fccafa5 Mon Sep 17 00:00:00 2001 From: "Luis R. Rodriguez" Date: Fri, 14 Jul 2017 14:50:08 -0700 Subject: kmod: add test driver to stress test the module loader This adds a new stress test driver for kmod: the kernel module loader. The new stress test driver, test_kmod, is only enabled as a module right now. It should be possible to load this as built-in and load tests early (refer to the force_init_test module parameter), however since a lot of test can get a system out of memory fast we leave this disabled for now. Using a system with 1024 MiB of RAM can *easily* get your kernel OOM fast with this test driver. The test_kmod driver exposes API knobs for us to fine tune simple request_module() and get_fs_type() calls. Since these API calls only allow each one parameter a test driver for these is rather simple. Other factors that can help out test driver though are the number of calls we issue and knowing current limitations of each. This exposes configuration as much as possible through userspace to be able to build tests directly from userspace. Since it allows multiple misc devices its will eventually (once we add a knob to let us create new devices at will) also be possible to perform more tests in parallel, provided you have enough memory. We only enable tests we know work as of right now. Demo screenshots: # tools/testing/selftests/kmod/kmod.sh kmod_test_0001_driver: OK! - loading kmod test kmod_test_0001_driver: OK! - Return value: 256 (MODULE_NOT_FOUND), expected MODULE_NOT_FOUND kmod_test_0001_fs: OK! - loading kmod test kmod_test_0001_fs: OK! - Return value: -22 (-EINVAL), expected -EINVAL kmod_test_0002_driver: OK! - loading kmod test kmod_test_0002_driver: OK! - Return value: 256 (MODULE_NOT_FOUND), expected MODULE_NOT_FOUND kmod_test_0002_fs: OK! - loading kmod test kmod_test_0002_fs: OK! - Return value: -22 (-EINVAL), expected -EINVAL kmod_test_0003: OK! - loading kmod test kmod_test_0003: OK! - Return value: 0 (SUCCESS), expected SUCCESS kmod_test_0004: OK! - loading kmod test kmod_test_0004: OK! - Return value: 0 (SUCCESS), expected SUCCESS kmod_test_0005: OK! - loading kmod test kmod_test_0005: OK! - Return value: 0 (SUCCESS), expected SUCCESS kmod_test_0006: OK! - loading kmod test kmod_test_0006: OK! - Return value: 0 (SUCCESS), expected SUCCESS kmod_test_0005: OK! - loading kmod test kmod_test_0005: OK! - Return value: 0 (SUCCESS), expected SUCCESS kmod_test_0006: OK! - loading kmod test kmod_test_0006: OK! - Return value: 0 (SUCCESS), expected SUCCESS XXX: add test restult for 0007 Test completed You can also request for specific tests: # tools/testing/selftests/kmod/kmod.sh -t 0001 kmod_test_0001_driver: OK! - loading kmod test kmod_test_0001_driver: OK! - Return value: 256 (MODULE_NOT_FOUND), expected MODULE_NOT_FOUND kmod_test_0001_fs: OK! - loading kmod test kmod_test_0001_fs: OK! - Return value: -22 (-EINVAL), expected -EINVAL Test completed Lastly, the current available number of tests: # tools/testing/selftests/kmod/kmod.sh --help Usage: tools/testing/selftests/kmod/kmod.sh [ -t <4-number-digit> ] Valid tests: 0001-0009 0001 - Simple test - 1 thread for empty string 0002 - Simple test - 1 thread for modules/filesystems that do not exist 0003 - Simple test - 1 thread for get_fs_type() only 0004 - Simple test - 2 threads for get_fs_type() only 0005 - multithreaded tests with default setup - request_module() only 0006 - multithreaded tests with default setup - get_fs_type() only 0007 - multithreaded tests with default setup test request_module() and get_fs_type() 0008 - multithreaded - push kmod_concurrent over max_modprobes for request_module() 0009 - multithreaded - push kmod_concurrent over max_modprobes for get_fs_type() The following test cases currently fail, as such they are not currently enabled by default: # tools/testing/selftests/kmod/kmod.sh -t 0008 # tools/testing/selftests/kmod/kmod.sh -t 0009 To be sure to run them as intended please unload both of the modules: o test_module o xfs And ensure they are not loaded on your system prior to testing them. If you use these paritions for your rootfs you can change the default test driver used for get_fs_type() by exporting it into your environment. For example of other test defaults you can override refer to kmod.sh allow_user_defaults(). Behind the scenes this is how we fine tune at a test case prior to hitting a trigger to run it: cat /sys/devices/virtual/misc/test_kmod0/config echo -n "2" > /sys/devices/virtual/misc/test_kmod0/config_test_case echo -n "ext4" > /sys/devices/virtual/misc/test_kmod0/config_test_fs echo -n "80" > /sys/devices/virtual/misc/test_kmod0/config_num_threads cat /sys/devices/virtual/misc/test_kmod0/config echo -n "1" > /sys/devices/virtual/misc/test_kmod0/config_num_threads Finally to trigger: echo -n "1" > /sys/devices/virtual/misc/test_kmod0/trigger_config The kmod.sh script uses the above constructs to build different test cases. A bit of interpretation of the current failures follows, first two premises: a) When request_module() is used userspace figures out an optimized version of module order for us. Once it finds the modules it needs, as per depmod symbol dep map, it will finit_module() the respective modules which are needed for the original request_module() request. b) We have an optimization in place whereby if a kernel uses request_module() on a module already loaded we never bother userspace as the module already is loaded. This is all handled by kernel/kmod.c. A few things to consider to help identify root causes of issues: 0) kmod 19 has a broken heuristic for modules being assumed to be built-in to your kernel and will return 0 even though request_module() failed. Upgrade to a newer version of kmod. 1) A get_fs_type() call for "xfs" will request_module() for "fs-xfs", not for "xfs". The optimization in kernel described in b) fails to catch if we have a lot of consecutive get_fs_type() calls. The reason is the optimization in place does not look for aliases. This means two consecutive get_fs_type() calls will bump kmod_concurrent, whereas request_module() will not. This one explanation why test case 0009 fails at least once for get_fs_type(). 2) If a module fails to load --- for whatever reason (kmod_concurrent limit reached, file not yet present due to rootfs switch, out of memory) we have a period of time during which module request for the same name either with request_module() or get_fs_type() will *also* fail to load even if the file for the module is ready. This explains why *multiple* NULLs are possible on test 0009. 3) finit_module() consumes quite a bit of memory. 4) Filesystems typically also have more dependent modules than other modules, its important to note though that even though a get_fs_type() call does not incur additional kmod_concurrent bumps, since userspace loads dependencies it finds it needs via finit_module_fd(), it *will* take much more memory to load a module with a lot of dependencies. Because of 3) and 4) we will easily run into out of memory failures with certain tests. For instance test 0006 fails on qemu with 1024 MiB of RAM. It panics a box after reaping all userspace processes and still not having enough memory to reap. [arnd@arndb.de: add dependencies for test module] Link: http://lkml.kernel.org/r/20170630154834.3689272-1-arnd@arndb.de Link: http://lkml.kernel.org/r/20170628223155.26472-3-mcgrof@kernel.org Signed-off-by: Luis R. Rodriguez Cc: Jessica Yu Cc: Shuah Khan Cc: Rusty Russell Cc: Michal Marek Cc: Petr Mladek Cc: Greg Kroah-Hartman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- MAINTAINERS | 2 + lib/Kconfig.debug | 27 + lib/Makefile | 1 + lib/test_kmod.c | 1246 +++++++++++++++++++++++++++++++++ tools/testing/selftests/kmod/Makefile | 11 + tools/testing/selftests/kmod/config | 7 + tools/testing/selftests/kmod/kmod.sh | 635 +++++++++++++++++ 7 files changed, 1929 insertions(+) create mode 100644 lib/test_kmod.c create mode 100644 tools/testing/selftests/kmod/Makefile create mode 100644 tools/testing/selftests/kmod/config create mode 100644 tools/testing/selftests/kmod/kmod.sh (limited to 'lib/Kconfig.debug') diff --git a/MAINTAINERS b/MAINTAINERS index c917d4161427..0876084a97da 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -7560,6 +7560,8 @@ L: linux-kernel@vger.kernel.org S: Maintained F: kernel/kmod.c F: include/linux/kmod.h +F: lib/test_kmod.c +F: tools/testing/selftests/kmod/ KPROBES M: Ananth N Mavinakayanahalli diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index b0d01c6d4e03..789c6e9e5e01 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1847,6 +1847,33 @@ config BUG_ON_DATA_CORRUPTION If unsure, say N. +config TEST_KMOD + tristate "kmod stress tester" + default n + depends on m + depends on BLOCK && (64BIT || LBDAF) # for XFS, BTRFS + depends on NETDEVICES && NET_CORE && INET # for TUN + select TEST_LKM + select XFS_FS + select TUN + select BTRFS_FS + help + Test the kernel's module loading mechanism: kmod. kmod implements + support to load modules using the Linux kernel's usermode helper. + This test provides a series of tests against kmod. + + Although technically you can either build test_kmod as a module or + into the kernel we disallow building it into the kernel since + it stress tests request_module() and this will very likely cause + some issues by taking over precious threads available from other + module load requests, ultimately this could be fatal. + + To run tests run: + + tools/testing/selftests/kmod/kmod.sh --help + + If unsure, say N. + source "samples/Kconfig" source "lib/Kconfig.kgdb" diff --git a/lib/Makefile b/lib/Makefile index 85e91e51a9fe..40c18372b301 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -61,6 +61,7 @@ obj-$(CONFIG_TEST_PRINTF) += test_printf.o obj-$(CONFIG_TEST_BITMAP) += test_bitmap.o obj-$(CONFIG_TEST_UUID) += test_uuid.o obj-$(CONFIG_TEST_PARMAN) += test_parman.o +obj-$(CONFIG_TEST_KMOD) += test_kmod.o ifeq ($(CONFIG_DEBUG_KOBJECT),y) CFLAGS_kobject.o += -DDEBUG diff --git a/lib/test_kmod.c b/lib/test_kmod.c new file mode 100644 index 000000000000..6c1d678bcf8b --- /dev/null +++ b/lib/test_kmod.c @@ -0,0 +1,1246 @@ +/* + * kmod stress test driver + * + * Copyright (C) 2017 Luis R. Rodriguez + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or at your option any + * later version; or, when distributed separately from the Linux kernel or + * when incorporated into other software packages, subject to the following + * license: + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of copyleft-next (version 0.3.1 or later) as published + * at http://copyleft-next.org/. + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +/* + * This driver provides an interface to trigger and test the kernel's + * module loader through a series of configurations and a few triggers. + * To test this driver use the following script as root: + * + * tools/testing/selftests/kmod/kmod.sh --help + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define TEST_START_NUM_THREADS 50 +#define TEST_START_DRIVER "test_module" +#define TEST_START_TEST_FS "xfs" +#define TEST_START_TEST_CASE TEST_KMOD_DRIVER + + +static bool force_init_test = false; +module_param(force_init_test, bool_enable_only, 0644); +MODULE_PARM_DESC(force_init_test, + "Force kicking a test immediately after driver loads"); + +/* + * For device allocation / registration + */ +static DEFINE_MUTEX(reg_dev_mutex); +static LIST_HEAD(reg_test_devs); + +/* + * num_test_devs actually represents the *next* ID of the next + * device we will allow to create. + */ +static int num_test_devs; + +/** + * enum kmod_test_case - linker table test case + * + * If you add a test case, please be sure to review if you need to se + * @need_mod_put for your tests case. + * + * @TEST_KMOD_DRIVER: stress tests request_module() + * @TEST_KMOD_FS_TYPE: stress tests get_fs_type() + */ +enum kmod_test_case { + __TEST_KMOD_INVALID = 0, + + TEST_KMOD_DRIVER, + TEST_KMOD_FS_TYPE, + + __TEST_KMOD_MAX, +}; + +struct test_config { + char *test_driver; + char *test_fs; + unsigned int num_threads; + enum kmod_test_case test_case; + int test_result; +}; + +struct kmod_test_device; + +/** + * kmod_test_device_info - thread info + * + * @ret_sync: return value if request_module() is used, sync request for + * @TEST_KMOD_DRIVER + * @fs_sync: return value of get_fs_type() for @TEST_KMOD_FS_TYPE + * @thread_idx: thread ID + * @test_dev: test device test is being performed under + * @need_mod_put: Some tests (get_fs_type() is one) requires putting the module + * (module_put(fs_sync->owner)) when done, otherwise you will not be able + * to unload the respective modules and re-test. We use this to keep + * accounting of when we need this and to help out in case we need to + * error out and deal with module_put() on error. + */ +struct kmod_test_device_info { + int ret_sync; + struct file_system_type *fs_sync; + struct task_struct *task_sync; + unsigned int thread_idx; + struct kmod_test_device *test_dev; + bool need_mod_put; +}; + +/** + * kmod_test_device - test device to help test kmod + * + * @dev_idx: unique ID for test device + * @config: configuration for the test + * @misc_dev: we use a misc device under the hood + * @dev: pointer to misc_dev's own struct device + * @config_mutex: protects configuration of test + * @trigger_mutex: the test trigger can only be fired once at a time + * @thread_lock: protects @done count, and the @info per each thread + * @done: number of threads which have completed or failed + * @test_is_oom: when we run out of memory, use this to halt moving forward + * @kthreads_done: completion used to signal when all work is done + * @list: needed to be part of the reg_test_devs + * @info: array of info for each thread + */ +struct kmod_test_device { + int dev_idx; + struct test_config config; + struct miscdevice misc_dev; + struct device *dev; + struct mutex config_mutex; + struct mutex trigger_mutex; + struct mutex thread_mutex; + + unsigned int done; + + bool test_is_oom; + struct completion kthreads_done; + struct list_head list; + + struct kmod_test_device_info *info; +}; + +static const char *test_case_str(enum kmod_test_case test_case) +{ + switch (test_case) { + case TEST_KMOD_DRIVER: + return "TEST_KMOD_DRIVER"; + case TEST_KMOD_FS_TYPE: + return "TEST_KMOD_FS_TYPE"; + default: + return "invalid"; + } +} + +static struct miscdevice *dev_to_misc_dev(struct device *dev) +{ + return dev_get_drvdata(dev); +} + +static struct kmod_test_device *misc_dev_to_test_dev(struct miscdevice *misc_dev) +{ + return container_of(misc_dev, struct kmod_test_device, misc_dev); +} + +static struct kmod_test_device *dev_to_test_dev(struct device *dev) +{ + struct miscdevice *misc_dev; + + misc_dev = dev_to_misc_dev(dev); + + return misc_dev_to_test_dev(misc_dev); +} + +/* Must run with thread_mutex held */ +static void kmod_test_done_check(struct kmod_test_device *test_dev, + unsigned int idx) +{ + struct test_config *config = &test_dev->config; + + test_dev->done++; + dev_dbg(test_dev->dev, "Done thread count: %u\n", test_dev->done); + + if (test_dev->done == config->num_threads) { + dev_info(test_dev->dev, "Done: %u threads have all run now\n", + test_dev->done); + dev_info(test_dev->dev, "Last thread to run: %u\n", idx); + complete(&test_dev->kthreads_done); + } +} + +static void test_kmod_put_module(struct kmod_test_device_info *info) +{ + struct kmod_test_device *test_dev = info->test_dev; + struct test_config *config = &test_dev->config; + + if (!info->need_mod_put) + return; + + switch (config->test_case) { + case TEST_KMOD_DRIVER: + break; + case TEST_KMOD_FS_TYPE: + if (info && info->fs_sync && info->fs_sync->owner) + module_put(info->fs_sync->owner); + break; + default: + BUG(); + } + + info->need_mod_put = true; +} + +static int run_request(void *data) +{ + struct kmod_test_device_info *info = data; + struct kmod_test_device *test_dev = info->test_dev; + struct test_config *config = &test_dev->config; + + switch (config->test_case) { + case TEST_KMOD_DRIVER: + info->ret_sync = request_module("%s", config->test_driver); + break; + case TEST_KMOD_FS_TYPE: + info->fs_sync = get_fs_type(config->test_fs); + info->need_mod_put = true; + break; + default: + /* __trigger_config_run() already checked for test sanity */ + BUG(); + return -EINVAL; + } + + dev_dbg(test_dev->dev, "Ran thread %u\n", info->thread_idx); + + test_kmod_put_module(info); + + mutex_lock(&test_dev->thread_mutex); + info->task_sync = NULL; + kmod_test_done_check(test_dev, info->thread_idx); + mutex_unlock(&test_dev->thread_mutex); + + return 0; +} + +static int tally_work_test(struct kmod_test_device_info *info) +{ + struct kmod_test_device *test_dev = info->test_dev; + struct test_config *config = &test_dev->config; + int err_ret = 0; + + switch (config->test_case) { + case TEST_KMOD_DRIVER: + /* + * Only capture errors, if one is found that's + * enough, for now. + */ + if (info->ret_sync != 0) + err_ret = info->ret_sync; + dev_info(test_dev->dev, + "Sync thread %d return status: %d\n", + info->thread_idx, info->ret_sync); + break; + case TEST_KMOD_FS_TYPE: + /* For now we make this simple */ + if (!info->fs_sync) + err_ret = -EINVAL; + dev_info(test_dev->dev, "Sync thread %u fs: %s\n", + info->thread_idx, info->fs_sync ? config->test_fs : + "NULL"); + break; + default: + BUG(); + } + + return err_ret; +} + +/* + * XXX: add result option to display if all errors did not match. + * For now we just keep any error code if one was found. + * + * If this ran it means *all* tasks were created fine and we + * are now just collecting results. + * + * Only propagate errors, do not override with a subsequent sucess case. + */ +static void tally_up_work(struct kmod_test_device *test_dev) +{ + struct test_config *config = &test_dev->config; + struct kmod_test_device_info *info; + unsigned int idx; + int err_ret = 0; + int ret = 0; + + mutex_lock(&test_dev->thread_mutex); + + dev_info(test_dev->dev, "Results:\n"); + + for (idx=0; idx < config->num_threads; idx++) { + info = &test_dev->info[idx]; + ret = tally_work_test(info); + if (ret) + err_ret = ret; + } + + /* + * Note: request_module() returns 256 for a module not found even + * though modprobe itself returns 1. + */ + config->test_result = err_ret; + + mutex_unlock(&test_dev->thread_mutex); +} + +static int try_one_request(struct kmod_test_device *test_dev, unsigned int idx) +{ + struct kmod_test_device_info *info = &test_dev->info[idx]; + int fail_ret = -ENOMEM; + + mutex_lock(&test_dev->thread_mutex); + + info->thread_idx = idx; + info->test_dev = test_dev; + info->task_sync = kthread_run(run_request, info, "%s-%u", + KBUILD_MODNAME, idx); + + if (!info->task_sync || IS_ERR(info->task_sync)) { + test_dev->test_is_oom = true; + dev_err(test_dev->dev, "Setting up thread %u failed\n", idx); + info->task_sync = NULL; + goto err_out; + } else + dev_dbg(test_dev->dev, "Kicked off thread %u\n", idx); + + mutex_unlock(&test_dev->thread_mutex); + + return 0; + +err_out: + info->ret_sync = fail_ret; + mutex_unlock(&test_dev->thread_mutex); + + return fail_ret; +} + +static void test_dev_kmod_stop_tests(struct kmod_test_device *test_dev) +{ + struct test_config *config = &test_dev->config; + struct kmod_test_device_info *info; + unsigned int i; + + dev_info(test_dev->dev, "Ending request_module() tests\n"); + + mutex_lock(&test_dev->thread_mutex); + + for (i=0; i < config->num_threads; i++) { + info = &test_dev->info[i]; + if (info->task_sync && !IS_ERR(info->task_sync)) { + dev_info(test_dev->dev, + "Stopping still-running thread %i\n", i); + kthread_stop(info->task_sync); + } + + /* + * info->task_sync is well protected, it can only be + * NULL or a pointer to a struct. If its NULL we either + * never ran, or we did and we completed the work. Completed + * tasks *always* put the module for us. This is a sanity + * check -- just in case. + */ + if (info->task_sync && info->need_mod_put) + test_kmod_put_module(info); + } + + mutex_unlock(&test_dev->thread_mutex); +} + +/* + * Only wait *iff* we did not run into any errors during all of our thread + * set up. If run into any issues we stop threads and just bail out with + * an error to the trigger. This also means we don't need any tally work + * for any threads which fail. + */ +static int try_requests(struct kmod_test_device *test_dev) +{ + struct test_config *config = &test_dev->config; + unsigned int idx; + int ret; + bool any_error = false; + + for (idx=0; idx < config->num_threads; idx++) { + if (test_dev->test_is_oom) { + any_error = true; + break; + } + + ret = try_one_request(test_dev, idx); + if (ret) { + any_error = true; + break; + } + } + + if (!any_error) { + test_dev->test_is_oom = false; + dev_info(test_dev->dev, + "No errors were found while initializing threads\n"); + wait_for_completion(&test_dev->kthreads_done); + tally_up_work(test_dev); + } else { + test_dev->test_is_oom = true; + dev_info(test_dev->dev, + "At least one thread failed to start, stop all work\n"); + test_dev_kmod_stop_tests(test_dev); + return -ENOMEM; + } + + return 0; +} + +static int run_test_driver(struct kmod_test_device *test_dev) +{ + struct test_config *config = &test_dev->config; + + dev_info(test_dev->dev, "Test case: %s (%u)\n", + test_case_str(config->test_case), + config->test_case); + dev_info(test_dev->dev, "Test driver to load: %s\n", + config->test_driver); + dev_info(test_dev->dev, "Number of threads to run: %u\n", + config->num_threads); + dev_info(test_dev->dev, "Thread IDs will range from 0 - %u\n", + config->num_threads - 1); + + return try_requests(test_dev); +} + +static int run_test_fs_type(struct kmod_test_device *test_dev) +{ + struct test_config *config = &test_dev->config; + + dev_info(test_dev->dev, "Test case: %s (%u)\n", + test_case_str(config->test_case), + config->test_case); + dev_info(test_dev->dev, "Test filesystem to load: %s\n", + config->test_fs); + dev_info(test_dev->dev, "Number of threads to run: %u\n", + config->num_threads); + dev_info(test_dev->dev, "Thread IDs will range from 0 - %u\n", + config->num_threads - 1); + + return try_requests(test_dev); +} + +static ssize_t config_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct kmod_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + int len = 0; + + mutex_lock(&test_dev->config_mutex); + + len += snprintf(buf, PAGE_SIZE, + "Custom trigger configuration for: %s\n", + dev_name(dev)); + + len += snprintf(buf+len, PAGE_SIZE - len, + "Number of threads:\t%u\n", + config->num_threads); + + len += snprintf(buf+len, PAGE_SIZE - len, + "Test_case:\t%s (%u)\n", + test_case_str(config->test_case), + config->test_case); + + if (config->test_driver) + len += snprintf(buf+len, PAGE_SIZE - len, + "driver:\t%s\n", + config->test_driver); + else + len += snprintf(buf+len, PAGE_SIZE - len, + "driver:\tEMTPY\n"); + + if (config->test_fs) + len += snprintf(buf+len, PAGE_SIZE - len, + "fs:\t%s\n", + config->test_fs); + else + len += snprintf(buf+len, PAGE_SIZE - len, + "fs:\tEMTPY\n"); + + mutex_unlock(&test_dev->config_mutex); + + return len; +} +static DEVICE_ATTR_RO(config); + +/* + * This ensures we don't allow kicking threads through if our configuration + * is faulty. + */ +static int __trigger_config_run(struct kmod_test_device *test_dev) +{ + struct test_config *config = &test_dev->config; + + test_dev->done = 0; + + switch (config->test_case) { + case TEST_KMOD_DRIVER: + return run_test_driver(test_dev); + case TEST_KMOD_FS_TYPE: + return run_test_fs_type(test_dev); + default: + dev_warn(test_dev->dev, + "Invalid test case requested: %u\n", + config->test_case); + return -EINVAL; + } +} + +static int trigger_config_run(struct kmod_test_device *test_dev) +{ + struct test_config *config = &test_dev->config; + int ret; + + mutex_lock(&test_dev->trigger_mutex); + mutex_lock(&test_dev->config_mutex); + + ret = __trigger_config_run(test_dev); + if (ret < 0) + goto out; + dev_info(test_dev->dev, "General test result: %d\n", + config->test_result); + + /* + * We must return 0 after a trigger even unless something went + * wrong with the setup of the test. If the test setup went fine + * then userspace must just check the result of config->test_result. + * One issue with relying on the return from a call in the kernel + * is if the kernel returns a possitive value using this trigger + * will not return the value to userspace, it would be lost. + * + * By not relying on capturing the return value of tests we are using + * through the trigger it also us to run tests with set -e and only + * fail when something went wrong with the driver upon trigger + * requests. + */ + ret = 0; + +out: + mutex_unlock(&test_dev->config_mutex); + mutex_unlock(&test_dev->trigger_mutex); + + return ret; +} + +static ssize_t +trigger_config_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct kmod_test_device *test_dev = dev_to_test_dev(dev); + int ret; + + if (test_dev->test_is_oom) + return -ENOMEM; + + /* For all intents and purposes we don't care what userspace + * sent this trigger, we care only that we were triggered. + * We treat the return value only for caputuring issues with + * the test setup. At this point all the test variables should + * have been allocated so typically this should never fail. + */ + ret = trigger_config_run(test_dev); + if (unlikely(ret < 0)) + goto out; + + /* + * Note: any return > 0 will be treated as success + * and the error value will not be available to userspace. + * Do not rely on trying to send to userspace a test value + * return value as possitive return errors will be lost. + */ + if (WARN_ON(ret > 0)) + return -EINVAL; + + ret = count; +out: + return ret; +} +static DEVICE_ATTR_WO(trigger_config); + +/* + * XXX: move to kstrncpy() once merged. + * + * Users should use kfree_const() when freeing these. + */ +static int __kstrncpy(char **dst, const char *name, size_t count, gfp_t gfp) +{ + *dst = kstrndup(name, count, gfp); + if (!*dst) + return -ENOSPC; + return count; +} + +static int config_copy_test_driver_name(struct test_config *config, + const char *name, + size_t count) +{ + return __kstrncpy(&config->test_driver, name, count, GFP_KERNEL); +} + + +static int config_copy_test_fs(struct test_config *config, const char *name, + size_t count) +{ + return __kstrncpy(&config->test_fs, name, count, GFP_KERNEL); +} + +static void __kmod_config_free(struct test_config *config) +{ + if (!config) + return; + + kfree_const(config->test_driver); + config->test_driver = NULL; + + kfree_const(config->test_fs); + config->test_driver = NULL; +} + +static void kmod_config_free(struct kmod_test_device *test_dev) +{ + struct test_config *config; + + if (!test_dev) + return; + + config = &test_dev->config; + + mutex_lock(&test_dev->config_mutex); + __kmod_config_free(config); + mutex_unlock(&test_dev->config_mutex); +} + +static ssize_t config_test_driver_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct kmod_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + int copied; + + mutex_lock(&test_dev->config_mutex); + + kfree_const(config->test_driver); + config->test_driver = NULL; + + copied = config_copy_test_driver_name(config, buf, count); + mutex_unlock(&test_dev->config_mutex); + + return copied; +} + +/* + * As per sysfs_kf_seq_show() the buf is max PAGE_SIZE. + */ +static ssize_t config_test_show_str(struct mutex *config_mutex, + char *dst, + char *src) +{ + int len; + + mutex_lock(config_mutex); + len = snprintf(dst, PAGE_SIZE, "%s\n", src); + mutex_unlock(config_mutex); + + return len; +} + +static ssize_t config_test_driver_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct kmod_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + + return config_test_show_str(&test_dev->config_mutex, buf, + config->test_driver); +} +static DEVICE_ATTR(config_test_driver, 0644, config_test_driver_show, + config_test_driver_store); + +static ssize_t config_test_fs_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct kmod_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + int copied; + + mutex_lock(&test_dev->config_mutex); + + kfree_const(config->test_fs); + config->test_fs = NULL; + + copied = config_copy_test_fs(config, buf, count); + mutex_unlock(&test_dev->config_mutex); + + return copied; +} + +static ssize_t config_test_fs_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct kmod_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + + return config_test_show_str(&test_dev->config_mutex, buf, + config->test_fs); +} +static DEVICE_ATTR(config_test_fs, 0644, config_test_fs_show, + config_test_fs_store); + +static int trigger_config_run_type(struct kmod_test_device *test_dev, + enum kmod_test_case test_case, + const char *test_str) +{ + int copied = 0; + struct test_config *config = &test_dev->config; + + mutex_lock(&test_dev->config_mutex); + + switch (test_case) { + case TEST_KMOD_DRIVER: + kfree_const(config->test_driver); + config->test_driver = NULL; + copied = config_copy_test_driver_name(config, test_str, + strlen(test_str)); + break; + case TEST_KMOD_FS_TYPE: + break; + kfree_const(config->test_fs); + config->test_driver = NULL; + copied = config_copy_test_fs(config, test_str, + strlen(test_str)); + default: + mutex_unlock(&test_dev->config_mutex); + return -EINVAL; + } + + config->test_case = test_case; + + mutex_unlock(&test_dev->config_mutex); + + if (copied <= 0 || copied != strlen(test_str)) { + test_dev->test_is_oom = true; + return -ENOMEM; + } + + test_dev->test_is_oom = false; + + return trigger_config_run(test_dev); +} + +static void free_test_dev_info(struct kmod_test_device *test_dev) +{ + vfree(test_dev->info); + test_dev->info = NULL; +} + +static int kmod_config_sync_info(struct kmod_test_device *test_dev) +{ + struct test_config *config = &test_dev->config; + + free_test_dev_info(test_dev); + test_dev->info = vzalloc(config->num_threads * + sizeof(struct kmod_test_device_info)); + if (!test_dev->info) { + dev_err(test_dev->dev, "Cannot alloc test_dev info\n"); + return -ENOMEM; + } + + return 0; +} + +/* + * Old kernels may not have this, if you want to port this code to + * test it on older kernels. + */ +#ifdef get_kmod_umh_limit +static unsigned int kmod_init_test_thread_limit(void) +{ + return get_kmod_umh_limit(); +} +#else +static unsigned int kmod_init_test_thread_limit(void) +{ + return TEST_START_NUM_THREADS; +} +#endif + +static int __kmod_config_init(struct kmod_test_device *test_dev) +{ + struct test_config *config = &test_dev->config; + int ret = -ENOMEM, copied; + + __kmod_config_free(config); + + copied = config_copy_test_driver_name(config, TEST_START_DRIVER, + strlen(TEST_START_DRIVER)); + if (copied != strlen(TEST_START_DRIVER)) + goto err_out; + + copied = config_copy_test_fs(config, TEST_START_TEST_FS, + strlen(TEST_START_TEST_FS)); + if (copied != strlen(TEST_START_TEST_FS)) + goto err_out; + + config->num_threads = kmod_init_test_thread_limit(); + config->test_result = 0; + config->test_case = TEST_START_TEST_CASE; + + ret = kmod_config_sync_info(test_dev); + if (ret) + goto err_out; + + test_dev->test_is_oom = false; + + return 0; + +err_out: + test_dev->test_is_oom = true; + WARN_ON(test_dev->test_is_oom); + + __kmod_config_free(config); + + return ret; +} + +static ssize_t reset_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct kmod_test_device *test_dev = dev_to_test_dev(dev); + int ret; + + mutex_lock(&test_dev->trigger_mutex); + mutex_lock(&test_dev->config_mutex); + + ret = __kmod_config_init(test_dev); + if (ret < 0) { + ret = -ENOMEM; + dev_err(dev, "could not alloc settings for config trigger: %d\n", + ret); + goto out; + } + + dev_info(dev, "reset\n"); + ret = count; + +out: + mutex_unlock(&test_dev->config_mutex); + mutex_unlock(&test_dev->trigger_mutex); + + return ret; +} +static DEVICE_ATTR_WO(reset); + +static int test_dev_config_update_uint_sync(struct kmod_test_device *test_dev, + const char *buf, size_t size, + unsigned int *config, + int (*test_sync)(struct kmod_test_device *test_dev)) +{ + int ret; + long new; + unsigned int old_val; + + ret = kstrtol(buf, 10, &new); + if (ret) + return ret; + + if (new > UINT_MAX) + return -EINVAL; + + mutex_lock(&test_dev->config_mutex); + + old_val = *config; + *(unsigned int *)config = new; + + ret = test_sync(test_dev); + if (ret) { + *(unsigned int *)config = old_val; + + ret = test_sync(test_dev); + WARN_ON(ret); + + mutex_unlock(&test_dev->config_mutex); + return -EINVAL; + } + + mutex_unlock(&test_dev->config_mutex); + /* Always return full write size even if we didn't consume all */ + return size; +} + +static int test_dev_config_update_uint_range(struct kmod_test_device *test_dev, + const char *buf, size_t size, + unsigned int *config, + unsigned int min, + unsigned int max) +{ + int ret; + long new; + + ret = kstrtol(buf, 10, &new); + if (ret) + return ret; + + if (new < min || new > max || new > UINT_MAX) + return -EINVAL; + + mutex_lock(&test_dev->config_mutex); + *config = new; + mutex_unlock(&test_dev->config_mutex); + + /* Always return full write size even if we didn't consume all */ + return size; +} + +static int test_dev_config_update_int(struct kmod_test_device *test_dev, + const char *buf, size_t size, + int *config) +{ + int ret; + long new; + + ret = kstrtol(buf, 10, &new); + if (ret) + return ret; + + if (new > INT_MAX || new < INT_MIN) + return -EINVAL; + + mutex_lock(&test_dev->config_mutex); + *config = new; + mutex_unlock(&test_dev->config_mutex); + /* Always return full write size even if we didn't consume all */ + return size; +} + +static ssize_t test_dev_config_show_int(struct kmod_test_device *test_dev, + char *buf, + int config) +{ + int val; + + mutex_lock(&test_dev->config_mutex); + val = config; + mutex_unlock(&test_dev->config_mutex); + + return snprintf(buf, PAGE_SIZE, "%d\n", val); +} + +static ssize_t test_dev_config_show_uint(struct kmod_test_device *test_dev, + char *buf, + unsigned int config) +{ + unsigned int val; + + mutex_lock(&test_dev->config_mutex); + val = config; + mutex_unlock(&test_dev->config_mutex); + + return snprintf(buf, PAGE_SIZE, "%u\n", val); +} + +static ssize_t test_result_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct kmod_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + + return test_dev_config_update_int(test_dev, buf, count, + &config->test_result); +} + +static ssize_t config_num_threads_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct kmod_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + + return test_dev_config_update_uint_sync(test_dev, buf, count, + &config->num_threads, + kmod_config_sync_info); +} + +static ssize_t config_num_threads_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct kmod_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + + return test_dev_config_show_int(test_dev, buf, config->num_threads); +} +static DEVICE_ATTR(config_num_threads, 0644, config_num_threads_show, + config_num_threads_store); + +static ssize_t config_test_case_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct kmod_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + + return test_dev_config_update_uint_range(test_dev, buf, count, + &config->test_case, + __TEST_KMOD_INVALID + 1, + __TEST_KMOD_MAX - 1); +} + +static ssize_t config_test_case_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct kmod_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + + return test_dev_config_show_uint(test_dev, buf, config->test_case); +} +static DEVICE_ATTR(config_test_case, 0644, config_test_case_show, + config_test_case_store); + +static ssize_t test_result_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct kmod_test_device *test_dev = dev_to_test_dev(dev); + struct test_config *config = &test_dev->config; + + return test_dev_config_show_int(test_dev, buf, config->test_result); +} +static DEVICE_ATTR(test_result, 0644, test_result_show, test_result_store); + +#define TEST_KMOD_DEV_ATTR(name) &dev_attr_##name.attr + +static struct attribute *test_dev_attrs[] = { + TEST_KMOD_DEV_ATTR(trigger_config), + TEST_KMOD_DEV_ATTR(config), + TEST_KMOD_DEV_ATTR(reset), + + TEST_KMOD_DEV_ATTR(config_test_driver), + TEST_KMOD_DEV_ATTR(config_test_fs), + TEST_KMOD_DEV_ATTR(config_num_threads), + TEST_KMOD_DEV_ATTR(config_test_case), + TEST_KMOD_DEV_ATTR(test_result), + + NULL, +}; + +ATTRIBUTE_GROUPS(test_dev); + +static int kmod_config_init(struct kmod_test_device *test_dev) +{ + int ret; + + mutex_lock(&test_dev->config_mutex); + ret = __kmod_config_init(test_dev); + mutex_unlock(&test_dev->config_mutex); + + return ret; +} + +static struct kmod_test_device *alloc_test_dev_kmod(int idx) +{ + int ret; + struct kmod_test_device *test_dev; + struct miscdevice *misc_dev; + + test_dev = vzalloc(sizeof(struct kmod_test_device)); + if (!test_dev) { + pr_err("Cannot alloc test_dev\n"); + goto err_out; + } + + mutex_init(&test_dev->config_mutex); + mutex_init(&test_dev->trigger_mutex); + mutex_init(&test_dev->thread_mutex); + + init_completion(&test_dev->kthreads_done); + + ret = kmod_config_init(test_dev); + if (ret < 0) { + pr_err("Cannot alloc kmod_config_init()\n"); + goto err_out_free; + } + + test_dev->dev_idx = idx; + misc_dev = &test_dev->misc_dev; + + misc_dev->minor = MISC_DYNAMIC_MINOR; + misc_dev->name = kasprintf(GFP_KERNEL, "test_kmod%d", idx); + if (!misc_dev->name) { + pr_err("Cannot alloc misc_dev->name\n"); + goto err_out_free_config; + } + misc_dev->groups = test_dev_groups; + + return test_dev; + +err_out_free_config: + free_test_dev_info(test_dev); + kmod_config_free(test_dev); +err_out_free: + vfree(test_dev); + test_dev = NULL; +err_out: + return NULL; +} + +static void free_test_dev_kmod(struct kmod_test_device *test_dev) +{ + if (test_dev) { + kfree_const(test_dev->misc_dev.name); + test_dev->misc_dev.name = NULL; + free_test_dev_info(test_dev); + kmod_config_free(test_dev); + vfree(test_dev); + test_dev = NULL; + } +} + +static struct kmod_test_device *register_test_dev_kmod(void) +{ + struct kmod_test_device *test_dev = NULL; + int ret; + + mutex_unlock(®_dev_mutex); + + /* int should suffice for number of devices, test for wrap */ + if (unlikely(num_test_devs + 1) < 0) { + pr_err("reached limit of number of test devices\n"); + goto out; + } + + test_dev = alloc_test_dev_kmod(num_test_devs); + if (!test_dev) + goto out; + + ret = misc_register(&test_dev->misc_dev); + if (ret) { + pr_err("could not register misc device: %d\n", ret); + free_test_dev_kmod(test_dev); + goto out; + } + + test_dev->dev = test_dev->misc_dev.this_device; + list_add_tail(&test_dev->list, ®_test_devs); + dev_info(test_dev->dev, "interface ready\n"); + + num_test_devs++; + +out: + mutex_unlock(®_dev_mutex); + + return test_dev; + +} + +static int __init test_kmod_init(void) +{ + struct kmod_test_device *test_dev; + int ret; + + test_dev = register_test_dev_kmod(); + if (!test_dev) { + pr_err("Cannot add first test kmod device\n"); + return -ENODEV; + } + + /* + * With some work we might be able to gracefully enable + * testing with this driver built-in, for now this seems + * rather risky. For those willing to try have at it, + * and enable the below. Good luck! If that works, try + * lowering the init level for more fun. + */ + if (force_init_test) { + ret = trigger_config_run_type(test_dev, + TEST_KMOD_DRIVER, "tun"); + if (WARN_ON(ret)) + return ret; + ret = trigger_config_run_type(test_dev, + TEST_KMOD_FS_TYPE, "btrfs"); + if (WARN_ON(ret)) + return ret; + } + + return 0; +} +late_initcall(test_kmod_init); + +static +void unregister_test_dev_kmod(struct kmod_test_device *test_dev) +{ + mutex_lock(&test_dev->trigger_mutex); + mutex_lock(&test_dev->config_mutex); + + test_dev_kmod_stop_tests(test_dev); + + dev_info(test_dev->dev, "removing interface\n"); + misc_deregister(&test_dev->misc_dev); + kfree(&test_dev->misc_dev.name); + + mutex_unlock(&test_dev->config_mutex); + mutex_unlock(&test_dev->trigger_mutex); + + free_test_dev_kmod(test_dev); +} + +static void __exit test_kmod_exit(void) +{ + struct kmod_test_device *test_dev, *tmp; + + mutex_lock(®_dev_mutex); + list_for_each_entry_safe(test_dev, tmp, ®_test_devs, list) { + list_del(&test_dev->list); + unregister_test_dev_kmod(test_dev); + } + mutex_unlock(®_dev_mutex); +} +module_exit(test_kmod_exit); + +MODULE_AUTHOR("Luis R. Rodriguez "); +MODULE_LICENSE("GPL"); diff --git a/tools/testing/selftests/kmod/Makefile b/tools/testing/selftests/kmod/Makefile new file mode 100644 index 000000000000..fa2ccc5fb3de --- /dev/null +++ b/tools/testing/selftests/kmod/Makefile @@ -0,0 +1,11 @@ +# Makefile for kmod loading selftests + +# No binaries, but make sure arg-less "make" doesn't trigger "run_tests" +all: + +TEST_PROGS := kmod.sh + +include ../lib.mk + +# Nothing to clean up. +clean: diff --git a/tools/testing/selftests/kmod/config b/tools/testing/selftests/kmod/config new file mode 100644 index 000000000000..259f4fd6b5e2 --- /dev/null +++ b/tools/testing/selftests/kmod/config @@ -0,0 +1,7 @@ +CONFIG_TEST_KMOD=m +CONFIG_TEST_LKM=m +CONFIG_XFS_FS=m + +# For the module parameter force_init_test is used +CONFIG_TUN=m +CONFIG_BTRFS_FS=m diff --git a/tools/testing/selftests/kmod/kmod.sh b/tools/testing/selftests/kmod/kmod.sh new file mode 100644 index 000000000000..10196a62ed09 --- /dev/null +++ b/tools/testing/selftests/kmod/kmod.sh @@ -0,0 +1,635 @@ +#!/bin/bash +# +# Copyright (C) 2017 Luis R. Rodriguez +# +# This program is free software; you can redistribute it and/or modify it +# under the terms of the GNU General Public License as published by the Free +# Software Foundation; either version 2 of the License, or at your option any +# later version; or, when distributed separately from the Linux kernel or +# when incorporated into other software packages, subject to the following +# license: +# +# This program is free software; you can redistribute it and/or modify it +# under the terms of copyleft-next (version 0.3.1 or later) as published +# at http://copyleft-next.org/. + +# This is a stress test script for kmod, the kernel module loader. It uses +# test_kmod which exposes a series of knobs for the API for us so we can +# tweak each test in userspace rather than in kernelspace. +# +# The way kmod works is it uses the kernel's usermode helper API to eventually +# call /sbin/modprobe. It has a limit of the number of concurrent calls +# possible. The kernel interface to load modules is request_module(), however +# mount uses get_fs_type(). Both behave slightly differently, but the +# differences are important enough to test each call separately. For this +# reason test_kmod starts by providing tests for both calls. +# +# The test driver test_kmod assumes a series of defaults which you can +# override by exporting to your environment prior running this script. +# For instance this script assumes you do not have xfs loaded upon boot. +# If this is false, export DEFAULT_KMOD_FS="ext4" prior to running this +# script if the filesyste module you don't have loaded upon bootup +# is ext4 instead. Refer to allow_user_defaults() for a list of user +# override variables possible. +# +# You'll want at least 4 GiB of RAM to expect to run these tests +# without running out of memory on them. For other requirements refer +# to test_reqs() + +set -e + +TEST_NAME="kmod" +TEST_DRIVER="test_${TEST_NAME}" +TEST_DIR=$(dirname $0) + +# This represents +# +# TEST_ID:TEST_COUNT:ENABLED +# +# TEST_ID: is the test id number +# TEST_COUNT: number of times we should run the test +# ENABLED: 1 if enabled, 0 otherwise +# +# Once these are enabled please leave them as-is. Write your own test, +# we have tons of space. +ALL_TESTS="0001:3:1" +ALL_TESTS="$ALL_TESTS 0002:3:1" +ALL_TESTS="$ALL_TESTS 0003:1:1" +ALL_TESTS="$ALL_TESTS 0004:1:1" +ALL_TESTS="$ALL_TESTS 0005:10:1" +ALL_TESTS="$ALL_TESTS 0006:10:1" +ALL_TESTS="$ALL_TESTS 0007:5:1" + +# Disabled tests: +# +# 0008 x 150 - multithreaded - push kmod_concurrent over max_modprobes for request_module()" +# Current best-effort failure interpretation: +# Enough module requests get loaded in place fast enough to reach over the +# max_modprobes limit and trigger a failure -- before we're even able to +# start processing pending requests. +ALL_TESTS="$ALL_TESTS 0008:150:0" + +# 0009 x 150 - multithreaded - push kmod_concurrent over max_modprobes for get_fs_type()" +# Current best-effort failure interpretation: +# +# get_fs_type() requests modules using aliases as such the optimization in +# place today to look for already loaded modules will not take effect and +# we end up requesting a new module to load, this bumps the kmod_concurrent, +# and in certain circumstances can lead to pushing the kmod_concurrent over +# the max_modprobe limit. +# +# This test fails much easier than test 0008 since the alias optimizations +# are not in place. +ALL_TESTS="$ALL_TESTS 0009:150:0" + +test_modprobe() +{ + if [ ! -d $DIR ]; then + echo "$0: $DIR not present" >&2 + echo "You must have the following enabled in your kernel:" >&2 + cat $TEST_DIR/config >&2 + exit 1 + fi +} + +function allow_user_defaults() +{ + if [ -z $DEFAULT_KMOD_DRIVER ]; then + DEFAULT_KMOD_DRIVER="test_module" + fi + + if [ -z $DEFAULT_KMOD_FS ]; then + DEFAULT_KMOD_FS="xfs" + fi + + if [ -z $PROC_DIR ]; then + PROC_DIR="/proc/sys/kernel/" + fi + + if [ -z $MODPROBE_LIMIT ]; then + MODPROBE_LIMIT=50 + fi + + if [ -z $DIR ]; then + DIR="/sys/devices/virtual/misc/${TEST_DRIVER}0/" + fi + + if [ -z $DEFAULT_NUM_TESTS ]; then + DEFAULT_NUM_TESTS=150 + fi + + MODPROBE_LIMIT_FILE="${PROC_DIR}/kmod-limit" +} + +test_reqs() +{ + if ! which modprobe 2> /dev/null > /dev/null; then + echo "$0: You need modprobe installed" >&2 + exit 1 + fi + + if ! which kmod 2> /dev/null > /dev/null; then + echo "$0: You need kmod installed" >&2 + exit 1 + fi + + # kmod 19 has a bad bug where it returns 0 when modprobe + # gets called *even* if the module was not loaded due to + # some bad heuristics. For details see: + # + # A work around is possible in-kernel but its rather + # complex. + KMOD_VERSION=$(kmod --version | awk '{print $3}') + if [[ $KMOD_VERSION -le 19 ]]; then + echo "$0: You need at least kmod 20" >&2 + echo "kmod <= 19 is buggy, for details see:" >&2 + echo "http://git.kernel.org/cgit/utils/kernel/kmod/kmod.git/commit/libkmod/libkmod-module.c?id=fd44a98ae2eb5eb32161088954ab21e58e19dfc4" >&2 + exit 1 + fi + + uid=$(id -u) + if [ $uid -ne 0 ]; then + echo $msg must be run as root >&2 + exit 0 + fi +} + +function load_req_mod() +{ + trap "test_modprobe" EXIT + + if [ ! -d $DIR ]; then + # Alanis: "Oh isn't it ironic?" + modprobe $TEST_DRIVER + fi +} + +test_finish() +{ + echo "Test completed" +} + +errno_name_to_val() +{ + case "$1" in + # kmod calls modprobe and upon of a module not found + # modprobe returns just 1... However in the kernel we + # *sometimes* see 256... + MODULE_NOT_FOUND) + echo 256;; + SUCCESS) + echo 0;; + -EPERM) + echo -1;; + -ENOENT) + echo -2;; + -EINVAL) + echo -22;; + -ERR_ANY) + echo -123456;; + *) + echo invalid;; + esac +} + +errno_val_to_name() + case "$1" in + 256) + echo MODULE_NOT_FOUND;; + 0) + echo SUCCESS;; + -1) + echo -EPERM;; + -2) + echo -ENOENT;; + -22) + echo -EINVAL;; + -123456) + echo -ERR_ANY;; + *) + echo invalid;; + esac + +config_set_test_case_driver() +{ + if ! echo -n 1 >$DIR/config_test_case; then + echo "$0: Unable to set to test case to driver" >&2 + exit 1 + fi +} + +config_set_test_case_fs() +{ + if ! echo -n 2 >$DIR/config_test_case; then + echo "$0: Unable to set to test case to fs" >&2 + exit 1 + fi +} + +config_num_threads() +{ + if ! echo -n $1 >$DIR/config_num_threads; then + echo "$0: Unable to set to number of threads" >&2 + exit 1 + fi +} + +config_get_modprobe_limit() +{ + if [[ -f ${MODPROBE_LIMIT_FILE} ]] ; then + MODPROBE_LIMIT=$(cat $MODPROBE_LIMIT_FILE) + fi + echo $MODPROBE_LIMIT +} + +config_num_thread_limit_extra() +{ + MODPROBE_LIMIT=$(config_get_modprobe_limit) + let EXTRA_LIMIT=$MODPROBE_LIMIT+$1 + config_num_threads $EXTRA_LIMIT +} + +# For special characters use printf directly, +# refer to kmod_test_0001 +config_set_driver() +{ + if ! echo -n $1 >$DIR/config_test_driver; then + echo "$0: Unable to set driver" >&2 + exit 1 + fi +} + +config_set_fs() +{ + if ! echo -n $1 >$DIR/config_test_fs; then + echo "$0: Unable to set driver" >&2 + exit 1 + fi +} + +config_get_driver() +{ + cat $DIR/config_test_driver +} + +config_get_test_result() +{ + cat $DIR/test_result +} + +config_reset() +{ + if ! echo -n "1" >"$DIR"/reset; then + echo "$0: reset shuld have worked" >&2 + exit 1 + fi +} + +config_show_config() +{ + echo "----------------------------------------------------" + cat "$DIR"/config + echo "----------------------------------------------------" +} + +config_trigger() +{ + if ! echo -n "1" >"$DIR"/trigger_config 2>/dev/null; then + echo "$1: FAIL - loading should have worked" + config_show_config + exit 1 + fi + echo "$1: OK! - loading kmod test" +} + +config_trigger_want_fail() +{ + if echo "1" > $DIR/trigger_config 2>/dev/null; then + echo "$1: FAIL - test case was expected to fail" + config_show_config + exit 1 + fi + echo "$1: OK! - kmod test case failed as expected" +} + +config_expect_result() +{ + RC=$(config_get_test_result) + RC_NAME=$(errno_val_to_name $RC) + + ERRNO_NAME=$2 + ERRNO=$(errno_name_to_val $ERRNO_NAME) + + if [[ $ERRNO_NAME = "-ERR_ANY" ]]; then + if [[ $RC -ge 0 ]]; then + echo "$1: FAIL, test expects $ERRNO_NAME - got $RC_NAME ($RC)" >&2 + config_show_config + exit 1 + fi + elif [[ $RC != $ERRNO ]]; then + echo "$1: FAIL, test expects $ERRNO_NAME ($ERRNO) - got $RC_NAME ($RC)" >&2 + config_show_config + exit 1 + fi + echo "$1: OK! - Return value: $RC ($RC_NAME), expected $ERRNO_NAME" +} + +kmod_defaults_driver() +{ + config_reset + modprobe -r $DEFAULT_KMOD_DRIVER + config_set_driver $DEFAULT_KMOD_DRIVER +} + +kmod_defaults_fs() +{ + config_reset + modprobe -r $DEFAULT_KMOD_FS + config_set_fs $DEFAULT_KMOD_FS + config_set_test_case_fs +} + +kmod_test_0001_driver() +{ + NAME='\000' + + kmod_defaults_driver + config_num_threads 1 + printf '\000' >"$DIR"/config_test_driver + config_trigger ${FUNCNAME[0]} + config_expect_result ${FUNCNAME[0]} MODULE_NOT_FOUND +} + +kmod_test_0001_fs() +{ + NAME='\000' + + kmod_defaults_fs + config_num_threads 1 + printf '\000' >"$DIR"/config_test_fs + config_trigger ${FUNCNAME[0]} + config_expect_result ${FUNCNAME[0]} -EINVAL +} + +kmod_test_0001() +{ + kmod_test_0001_driver + kmod_test_0001_fs +} + +kmod_test_0002_driver() +{ + NAME="nope-$DEFAULT_KMOD_DRIVER" + + kmod_defaults_driver + config_set_driver $NAME + config_num_threads 1 + config_trigger ${FUNCNAME[0]} + config_expect_result ${FUNCNAME[0]} MODULE_NOT_FOUND +} + +kmod_test_0002_fs() +{ + NAME="nope-$DEFAULT_KMOD_FS" + + kmod_defaults_fs + config_set_fs $NAME + config_trigger ${FUNCNAME[0]} + config_expect_result ${FUNCNAME[0]} -EINVAL +} + +kmod_test_0002() +{ + kmod_test_0002_driver + kmod_test_0002_fs +} + +kmod_test_0003() +{ + kmod_defaults_fs + config_num_threads 1 + config_trigger ${FUNCNAME[0]} + config_expect_result ${FUNCNAME[0]} SUCCESS +} + +kmod_test_0004() +{ + kmod_defaults_fs + config_num_threads 2 + config_trigger ${FUNCNAME[0]} + config_expect_result ${FUNCNAME[0]} SUCCESS +} + +kmod_test_0005() +{ + kmod_defaults_driver + config_trigger ${FUNCNAME[0]} + config_expect_result ${FUNCNAME[0]} SUCCESS +} + +kmod_test_0006() +{ + kmod_defaults_fs + config_trigger ${FUNCNAME[0]} + config_expect_result ${FUNCNAME[0]} SUCCESS +} + +kmod_test_0007() +{ + kmod_test_0005 + kmod_test_0006 +} + +kmod_test_0008() +{ + kmod_defaults_driver + MODPROBE_LIMIT=$(config_get_modprobe_limit) + let EXTRA=$MODPROBE_LIMIT/6 + config_num_thread_limit_extra $EXTRA + config_trigger ${FUNCNAME[0]} + config_expect_result ${FUNCNAME[0]} SUCCESS +} + +kmod_test_0009() +{ + kmod_defaults_fs + MODPROBE_LIMIT=$(config_get_modprobe_limit) + let EXTRA=$MODPROBE_LIMIT/4 + config_num_thread_limit_extra $EXTRA + config_trigger ${FUNCNAME[0]} + config_expect_result ${FUNCNAME[0]} SUCCESS +} + +list_tests() +{ + echo "Test ID list:" + echo + echo "TEST_ID x NUM_TEST" + echo "TEST_ID: Test ID" + echo "NUM_TESTS: Number of recommended times to run the test" + echo + echo "0001 x $(get_test_count 0001) - Simple test - 1 thread for empty string" + echo "0002 x $(get_test_count 0002) - Simple test - 1 thread for modules/filesystems that do not exist" + echo "0003 x $(get_test_count 0003) - Simple test - 1 thread for get_fs_type() only" + echo "0004 x $(get_test_count 0004) - Simple test - 2 threads for get_fs_type() only" + echo "0005 x $(get_test_count 0005) - multithreaded tests with default setup - request_module() only" + echo "0006 x $(get_test_count 0006) - multithreaded tests with default setup - get_fs_type() only" + echo "0007 x $(get_test_count 0007) - multithreaded tests with default setup test request_module() and get_fs_type()" + echo "0008 x $(get_test_count 0008) - multithreaded - push kmod_concurrent over max_modprobes for request_module()" + echo "0009 x $(get_test_count 0009) - multithreaded - push kmod_concurrent over max_modprobes for get_fs_type()" +} + +usage() +{ + NUM_TESTS=$(grep -o ' ' <<<"$ALL_TESTS" | grep -c .) + let NUM_TESTS=$NUM_TESTS+1 + MAX_TEST=$(printf "%04d\n" $NUM_TESTS) + echo "Usage: $0 [ -t <4-number-digit> ] | [ -w <4-number-digit> ] |" + echo " [ -s <4-number-digit> ] | [ -c <4-number-digit> " + echo " [ all ] [ -h | --help ] [ -l ]" + echo "" + echo "Valid tests: 0001-$MAX_TEST" + echo "" + echo " all Runs all tests (default)" + echo " -t Run test ID the number amount of times is recommended" + echo " -w Watch test ID run until it runs into an error" + echo " -c Run test ID once" + echo " -s Run test ID x test-count number of times" + echo " -l List all test ID list" + echo " -h|--help Help" + echo + echo "If an error every occurs execution will immediately terminate." + echo "If you are adding a new test try using -w first to" + echo "make sure the test passes a series of tests." + echo + echo Example uses: + echo + echo "${TEST_NAME}.sh -- executes all tests" + echo "${TEST_NAME}.sh -t 0008 -- Executes test ID 0008 number of times is recomended" + echo "${TEST_NAME}.sh -w 0008 -- Watch test ID 0008 run until an error occurs" + echo "${TEST_NAME}.sh -s 0008 -- Run test ID 0008 once" + echo "${TEST_NAME}.sh -c 0008 3 -- Run test ID 0008 three times" + echo + list_tests + exit 1 +} + +function test_num() +{ + re='^[0-9]+$' + if ! [[ $1 =~ $re ]]; then + usage + fi +} + +function get_test_count() +{ + test_num $1 + TEST_DATA=$(echo $ALL_TESTS | awk '{print $'$1'}') + LAST_TWO=${TEST_DATA#*:*} + echo ${LAST_TWO%:*} +} + +function get_test_enabled() +{ + test_num $1 + TEST_DATA=$(echo $ALL_TESTS | awk '{print $'$1'}') + echo ${TEST_DATA#*:*:} +} + +function run_all_tests() +{ + for i in $ALL_TESTS ; do + TEST_ID=${i%:*:*} + ENABLED=$(get_test_enabled $TEST_ID) + TEST_COUNT=$(get_test_count $TEST_ID) + if [[ $ENABLED -eq "1" ]]; then + test_case $TEST_ID $TEST_COUNT + fi + done +} + +function watch_log() +{ + if [ $# -ne 3 ]; then + clear + fi + date + echo "Running test: $2 - run #$1" +} + +function watch_case() +{ + i=0 + while [ 1 ]; do + + if [ $# -eq 1 ]; then + test_num $1 + watch_log $i ${TEST_NAME}_test_$1 + ${TEST_NAME}_test_$1 + else + watch_log $i all + run_all_tests + fi + let i=$i+1 + done +} + +function test_case() +{ + NUM_TESTS=$DEFAULT_NUM_TESTS + if [ $# -eq 2 ]; then + NUM_TESTS=$2 + fi + + i=0 + while [ $i -lt $NUM_TESTS ]; do + test_num $1 + watch_log $i ${TEST_NAME}_test_$1 noclear + RUN_TEST=${TEST_NAME}_test_$1 + $RUN_TEST + let i=$i+1 + done +} + +function parse_args() +{ + if [ $# -eq 0 ]; then + run_all_tests + else + if [[ "$1" = "all" ]]; then + run_all_tests + elif [[ "$1" = "-w" ]]; then + shift + watch_case $@ + elif [[ "$1" = "-t" ]]; then + shift + test_num $1 + test_case $1 $(get_test_count $1) + elif [[ "$1" = "-c" ]]; then + shift + test_num $1 + test_num $2 + test_case $1 $2 + elif [[ "$1" = "-s" ]]; then + shift + test_case $1 1 + elif [[ "$1" = "-l" ]]; then + list_tests + elif [[ "$1" = "-h" || "$1" = "--help" ]]; then + usage + else + usage + fi + fi +} + +test_reqs +allow_user_defaults +load_req_mod + +trap "test_finish" EXIT + +parse_args $@ + +exit 0 -- cgit v1.3-14-g43fede From eecabf567422eda02bd179f2707d8fe24f52d888 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Thu, 8 Jun 2017 04:16:59 -0400 Subject: random: suppress spammy warnings about unseeded randomness Unfortunately, on some models of some architectures getting a fully seeded CRNG is extremely difficult, and so this can result in dmesg getting spammed for a surprisingly long time. This is really bad from a security perspective, and so architecture maintainers really need to do what they can to get the CRNG seeded sooner after the system is booted. However, users can't do anything actionble to address this, and spamming the kernel messages log will only just annoy people. For developers who want to work on improving this situation, CONFIG_WARN_UNSEEDED_RANDOM has been renamed to CONFIG_WARN_ALL_UNSEEDED_RANDOM. By default the kernel will always print the first use of unseeded randomness. This way, hopefully the security obsessed will be happy that there is _some_ indication when the kernel boots there may be a potential issue with that architecture or subarchitecture. To see all uses of unseeded randomness, developers can enable CONFIG_WARN_ALL_UNSEEDED_RANDOM. Signed-off-by: Theodore Ts'o --- drivers/char/random.c | 56 +++++++++++++++++++++++++++++++++++---------------- lib/Kconfig.debug | 24 ++++++++++++++++------ 2 files changed, 57 insertions(+), 23 deletions(-) (limited to 'lib/Kconfig.debug') diff --git a/drivers/char/random.c b/drivers/char/random.c index fa5bbd5a7ca0..799d37981d99 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -436,6 +436,7 @@ static void _extract_crng(struct crng_state *crng, static void _crng_backtrack_protect(struct crng_state *crng, __u8 tmp[CHACHA20_BLOCK_SIZE], int used); static void process_random_ready_list(void); +static void _get_random_bytes(void *buf, int nbytes); /********************************************************************** * @@ -776,7 +777,7 @@ static void crng_initialize(struct crng_state *crng) _extract_entropy(&input_pool, &crng->state[4], sizeof(__u32) * 12, 0); else - get_random_bytes(&crng->state[4], sizeof(__u32) * 12); + _get_random_bytes(&crng->state[4], sizeof(__u32) * 12); for (i = 4; i < 16; i++) { if (!arch_get_random_seed_long(&rv) && !arch_get_random_long(&rv)) @@ -1466,6 +1467,30 @@ static ssize_t extract_entropy_user(struct entropy_store *r, void __user *buf, return ret; } +#define warn_unseeded_randomness(previous) \ + _warn_unseeded_randomness(__func__, (void *) _RET_IP_, (previous)) + +static void _warn_unseeded_randomness(const char *func_name, void *caller, + void **previous) +{ +#ifdef CONFIG_WARN_ALL_UNSEEDED_RANDOM + const bool print_once = false; +#else + static bool print_once __read_mostly; +#endif + + if (print_once || + crng_ready() || + (previous && (caller == READ_ONCE(*previous)))) + return; + WRITE_ONCE(*previous, caller); +#ifndef CONFIG_WARN_ALL_UNSEEDED_RANDOM + print_once = true; +#endif + pr_notice("random: %s called from %pF with crng_init=%d\n", + func_name, caller, crng_init); +} + /* * This function is the exported kernel interface. It returns some * number of good random numbers, suitable for key generation, seeding @@ -1476,15 +1501,10 @@ static ssize_t extract_entropy_user(struct entropy_store *r, void __user *buf, * wait_for_random_bytes() should be called and return 0 at least once * at any point prior. */ -void get_random_bytes(void *buf, int nbytes) +static void _get_random_bytes(void *buf, int nbytes) { __u8 tmp[CHACHA20_BLOCK_SIZE]; -#ifdef CONFIG_WARN_UNSEEDED_RANDOM - if (!crng_ready()) - printk(KERN_NOTICE "random: %pF get_random_bytes called " - "with crng_init = %d\n", (void *) _RET_IP_, crng_init); -#endif trace_get_random_bytes(nbytes, _RET_IP_); while (nbytes >= CHACHA20_BLOCK_SIZE) { @@ -1501,6 +1521,14 @@ void get_random_bytes(void *buf, int nbytes) crng_backtrack_protect(tmp, CHACHA20_BLOCK_SIZE); memzero_explicit(tmp, sizeof(tmp)); } + +void get_random_bytes(void *buf, int nbytes) +{ + static void *previous; + + warn_unseeded_randomness(&previous); + _get_random_bytes(buf, nbytes); +} EXPORT_SYMBOL(get_random_bytes); /* @@ -2064,6 +2092,7 @@ u64 get_random_u64(void) bool use_lock = READ_ONCE(crng_init) < 2; unsigned long flags = 0; struct batched_entropy *batch; + static void *previous; #if BITS_PER_LONG == 64 if (arch_get_random_long((unsigned long *)&ret)) @@ -2074,11 +2103,7 @@ u64 get_random_u64(void) return ret; #endif -#ifdef CONFIG_WARN_UNSEEDED_RANDOM - if (!crng_ready()) - printk(KERN_NOTICE "random: %pF get_random_u64 called " - "with crng_init = %d\n", (void *) _RET_IP_, crng_init); -#endif + warn_unseeded_randomness(&previous); batch = &get_cpu_var(batched_entropy_u64); if (use_lock) @@ -2102,15 +2127,12 @@ u32 get_random_u32(void) bool use_lock = READ_ONCE(crng_init) < 2; unsigned long flags = 0; struct batched_entropy *batch; + static void *previous; if (arch_get_random_int(&ret)) return ret; -#ifdef CONFIG_WARN_UNSEEDED_RANDOM - if (!crng_ready()) - printk(KERN_NOTICE "random: %pF get_random_u32 called " - "with crng_init = %d\n", (void *) _RET_IP_, crng_init); -#endif + warn_unseeded_randomness(&previous); batch = &get_cpu_var(batched_entropy_u32); if (use_lock) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c4159605bfbf..9d0a244074b9 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1209,10 +1209,9 @@ config STACKTRACE It is also used by various kernel debugging features that require stack trace generation. -config WARN_UNSEEDED_RANDOM - bool "Warn when kernel uses unseeded randomness" - default y - depends on DEBUG_KERNEL +config WARN_ALL_UNSEEDED_RANDOM + bool "Warn for all uses of unseeded randomness" + default n help Some parts of the kernel contain bugs relating to their use of cryptographically secure random numbers before it's actually possible @@ -1222,8 +1221,21 @@ config WARN_UNSEEDED_RANDOM are going wrong, so that they might contact developers about fixing it. - Say Y here, unless you simply do not care about using unseeded - randomness and do not want a potential warning message in your logs. + Unfortunately, on some models of some architectures getting + a fully seeded CRNG is extremely difficult, and so this can + result in dmesg getting spammed for a surprisingly long + time. This is really bad from a security perspective, and + so architecture maintainers really need to do what they can + to get the CRNG seeded sooner after the system is booted. + However, since users can not do anything actionble to + address this, by default the kernel will issue only a single + warning for the first use of unseeded randomness. + + Say Y here if you want to receive warnings for all uses of + unseeded randomness. This will be of use primarily for + those developers interersted in improving the security of + Linux kernels running on their architecture (or + subarchitecture). config DEBUG_KOBJECT bool "kobject debugging" -- cgit v1.3-14-g43fede